CN103554396A - Preparation method of lignin modified phenolic resin for molding compound - Google Patents

Abstract

The invention discloses a lignin modified phenolic resin for molding compound. The lignin modified phenolic resin can be prepared by the following method: mixing phenol, an acid catalyst and enzymolysis lignin, heating to 90 DEG C-160 DEG C, liquefying for 1-3 h, cooling to 70 DEG C, then adding formaldehyde into the reaction system, heating to 90-120 DEG C, reacting for 2-4 h, and carrying out vacuum distillation to obtain the lignin modified phenolic resin. The invention uses enzymolysis lignin in rich resource to partially substitute phenol to prepare phenolic resin, so as to obviously reduce cost. The lignin modified phenolic resin provided by the invention can be used for preparing molding compound, and has high mechanical properties, heat resistance and insulation.

Description

A kind of preparation method of lignin modified phenolic resin for molding compound

technical field

The invention relates to a phenolic resin and a preparation method thereof, in particular to a lignin-modified phenolic resin used in molding materials and a preparation method thereof. the

Background technique

Lignin is the only non-petroleum resource that can provide renewable aryl compounds in nature, and it is the second most abundant natural polymer after cellulose in the plant kingdom. Lignin molecules have many different types of active groups, which have the advantages of being renewable, degradable, and non-toxic. Enzymatic Hydrolysis Lignin (EHL for short) is a new type of lignin extracted from the residue of fuel ethanol produced by fermentation of plant straw. At present, most of the enzymatic lignin is used for incineration, not only its components have not been effectively used, but also pollute the environment. my country now produces 600 to 700 million tons of corn stalks per year, and the residue of fuel ethanol produced by fermentation of 1 ton of corn stalks can be obtained About 300 kilograms of lignin, so the efficient use of enzymatic lignin can not only make rational use of resources, but also replace petrochemical products and protect the environment. The lignin used in the present invention is derived from residues of fuel ethanol or butanol produced from agricultural waste such as corn cobs and corn stalks. the

Phenolic molding compound is a material with excellent heat resistance and good cost performance, and its main component is phenolic resin. Phenolic resin is formed by polycondensation of phenolic compounds and aldehyde compounds under the action of a catalyst. Due to its low price, heat resistance, ablation resistance, flame retardancy, and less combustion smoke, it is widely used in adhesives, coatings, and molding compounds. , laminated plastics, foamed plastics, and ion exchange resins. The production and use of phenolic resin will consume a large amount of petrochemical products, and bring a certain degree of pollution to the environment, affecting the entire ecosystem. The prices of phenol and formaldehyde, which are the main petrochemical products used in the production of phenolic resin, continue to increase, resulting in a sharp decline in the profits of my country's phenolic resin-related industries, which seriously affects the development of the phenolic resin industry. the

The use of natural biomass resources to research and develop phenolic molding compounds is of great significance. Cheng Xiansu et al. used organic solvent extraction and inorganic chemical treatment to separate and purify enzymatic lignin from the residue of microbial enzymatic hydrolysis of corn stalks, and prepare biomodified hot-melt phenolic resin. This method increases production costs. the

Contents of the invention

The object of the present invention is to provide a kind of preparation method of lignin modified phenolic resin used in the preparation of molding compound which is environment-friendly, low cost, good overall performance and high yield. The preparation method is simple and effectively utilizes biomass fuel ethanol or The residue produced in the butanol preparation process has low cost, and the molding compound prepared by using the raw material has good mechanical properties and insulation properties and low cost. the

The present invention adopts the following technical scheme: a preparation method of lignin-modified phenolic resin used in molding materials, which is prepared by the following method: mixing phenol, acid catalyst and lignin, heating to 90°C-160°C, and reacting 1 -3h, lower the temperature to 70°C, then add formaldehyde dropwise to the reaction system, heat to 90°C-120°C for 2-4h, and distill under reduced pressure to obtain lignin modified phenolic resin with a softening point of 90°C-105°C ; Wherein, the acid catalyst used is oxalic acid. the

The lignin used is the enzymatically hydrolyzed lignin by-product of bioethanol or biobutanol. the

The acid catalyst is 1-7% of the mass of phenol. the

The mass ratio of lignin and phenol is 10-50:100. the

The molar ratio of phenol to formaldehyde is 1:0.81-0.87. the

The formaldehyde used is formaldehyde with a mass percentage concentration of 37-40%. the

Beneficial effect:

1. Due to the increasingly tense energy issues, the research and development of biofuel ethanol or butanol has been paid attention to. Therefore, the effective use of enzymatic lignin can reduce the cost of biofuel enterprises and promote the development of my country's biofuel industry. The raw material lignin used in the present invention does not need to be purified, and the by-products of biofuel ethanol or butanol can be directly used, which not only reduces production costs, but also avoids environmental pollution caused by the use of organic solvents. the

2. The present invention partially replaces phenol and formaldehyde with the product obtained by enzymatic hydrolysis of lignin phenol liquefaction, and reacts under the action of a catalyst to obtain a phenolic resin product with low cost and low toxicity (reduced free phenol content). The molecular weight of lignin phenol liquefaction products decreases, and the content of phenolic structure increases. Compared with lignin macromolecules, it has the characteristics of high reactivity, fast reaction speed and high production efficiency. the

3. The yield of enzymatic lignin modified phenolic resin (64-70%) is higher than that of pure phenolic resin (61-63%). the

Detailed ways

A lignin-modified phenolic resin used in molding compounds, with a softening point of 90°C-105°C, a fluidity of 1-7cm, a polymerization speed of 60-100s, and a viscosity of 12-18mPa.s, which can be prepared by the following method Obtain: mix phenol, acid catalyst and enzymatic lignin, the mass ratio of lignin to phenol is 10-50:100, adjust the Ph value of the above reaction system to 1-3 by changing the addition amount of acid catalyst, and then heat to 90°C-160°C, react for 1-3h, cool down to 70°C, then add formaldehyde, the molar ratio of phenol to aldehyde is 1:0.81-0.87, adjust the reaction temperature to 90°C-120°C, react for 2-4h, reduce pressure Distillation, the water in the system and residual phenol and formaldehyde are distilled off to obtain lignin-modified phenolic resin. the

The lignin is enzymatically hydrolyzed lignin produced from bioethanol or biobutanol by-products by corn stalk fermentation. the

The acid catalyst is oxalic acid. the

The amount of catalyst used is 1%-7% of the mass of phenol. the

The aldehyde is formaldehyde with a concentration of 37-40%. the

The phenolic resin is a thermoplastic phenolic resin used for preparing molding materials. the

Example 1

A lignin-modified phenolic resin used in molding materials, the softening point temperature is 90°C-105°C, which can be prepared by the following method: mix phenol, acid catalyst and lignin, heat to 90°C-160°C, and react 1 -3h, lower the temperature to 70°C, add formaldehyde dropwise to the reaction system, heat to 90°C-120°C for 2-4h, and distill under reduced pressure to obtain lignin-modified phenolic resin. A lignin-modified phenolic resin is obtained. The lignin that participates in this reaction is enzymatic lignin, that is, the by-product of biofuel ethanol or butanol production, that is, the residue produced. the

Example 2

Add a certain amount of phenol, enzymatic lignin (33% of the mass of phenol) and oxalic acid (1% of the mass of phenol) into the reactor, the reaction temperature is 95°C, the reaction time is 2h, the temperature is lowered to 70°C, and then formaldehyde (phenolic aldehyde The molar ratio is 1:0.85), the reaction temperature is 100°C, the reaction time is 2h, and the lignin-modified phenolic resin is obtained by distillation under reduced pressure. The softening point is 93°C, the fluidity is 4.5cm, the polymerization speed is 70s, and the free phenol content is 4%. the

Example 3

Add a certain amount of phenol, enzymatic lignin (33% of phenol mass) and oxalic acid catalyst (3% of phenol mass) into the reactor, the reaction temperature is 130°C, the reaction time is 2h, the temperature is lowered to 70°C, and then formaldehyde ( The phenol-formaldehyde molar ratio is 1:0.85), the reaction temperature is 110°C, the reaction time is 2h, and the lignin-modified phenolic resin is obtained by distillation under reduced pressure. The softening point is 96°C, the fluidity is 4.3cm, the polymerization speed is 63s, and the free phenol content is 3.7%. the

Example 4

Add a certain amount of phenol, enzymatic lignin (10% of phenol mass) and oxalic acid catalyst (7% of phenol mass) into the reactor, the reaction temperature is 135°C, the reaction time is 2h, the temperature is lowered to 70°C, and then formaldehyde ( The phenol-formaldehyde molar ratio is 1:0.85), the reaction temperature is 120°C, the reaction time is 2h, and the lignin-modified phenolic resin is obtained by distillation under reduced pressure. The softening point is 98.5°C, the fluidity is 4.0cm, the polymerization speed is 60s, and the free phenol content is 3.8%. the

Example 5

Add a certain amount of phenol, enzymatic lignin (33% of phenol mass) and oxalic acid catalyst (3% of phenol mass) into the reactor, the reaction temperature is 155°C, the reaction time is 2h, the temperature is lowered to 70°C, and then formaldehyde ( The phenol-formaldehyde molar ratio is 1:0.85), the reaction temperature is 100°C, the reaction time is 2h, and the lignin-modified phenolic resin is obtained by distillation under reduced pressure. The softening point is 95°C, the fluidity is 4.1cm, the polymerization speed is 62s, and the free phenol content is 3.7%. the

Example 6

Add a certain amount of phenol, enzymatic lignin (25% of the mass of phenol) and oxalic acid catalyst (5% of the mass of phenol) into the reactor, the reaction temperature is 135°C, the reaction time is 2h, the temperature is lowered to 70°C, and then formaldehyde ( The molar ratio of phenol to formaldehyde is 1:0.85), the reaction temperature is 120°C, and the reaction time is 2 hours. The water and residual phenol are removed under normal pressure and then under pressure to obtain lignin-modified phenolic resin. The softening point is 94°C, the fluidity is 5.1cm, the polymerization speed is 69s, and the free phenol content is 4.2%. the

Example 7

Add a certain amount of phenol, enzymatic lignin (50% of the mass of phenol) and oxalic acid catalyst (5% of the mass of phenol) into the reactor, the reaction temperature is 135°C, the reaction time is 2h, the temperature is lowered to 70°C, and then formaldehyde ( The molar ratio of phenol to formaldehyde is 1:0.85), the reaction temperature is 115°C, and the reaction time is 2 hours. The water and residual phenol are removed under normal pressure and then under pressure to obtain lignin-modified phenolic resin. The softening point is 105°C, the fluidity is 3.8cm, the polymerization speed is 89s, and the free phenol content is 3.1%. the

Note: The national standards referenced by each indicator

HG/T 2753-1996 Determination of the flow distance of phenolic resin on a glass plate

HG 5-1338-80 Phenolic resin polymerization speed test method

GB/T 8146-2003 Test method for rosin (softening point). the

Claims (6)

1. the preparation method for the lignin modification resol of moulding compound, it is characterized in that, prepare by the following method: phenol, acid catalyst and xylogen are mixed, be heated to 90 ℃-160 ℃, reaction 1-3h, be cooled to 70 ℃, again formaldehyde is added drop-wise in reaction system, is heated to 90 ℃-120 ℃ reaction 2-4h, underpressure distillation, make lignin modification resol, 90 ℃-105 ℃ of softening temperatures; Wherein, acid catalyst used is oxalic acid.

2. the preparation method of the lignin modification resol for moulding compound according to claim 1, is characterized in that: xylogen used is for preparing bio-ethanol or biological butanol by product enzymolysis xylogen.

3. the preparation method of the lignin modification resol for moulding compound according to claim 1, is characterized in that: acid catalyst is the 1-7% of phenol quality.

4. the preparation method of the lignin modification resol for moulding compound according to claim 1, is characterized in that: the mass ratio of xylogen and phenol is 10-50:100.

5. the preparation method of the lignin modification resol for moulding compound according to claim 1, is characterized in that: described phenol and the mol ratio of formaldehyde are 1:0.81-0.87.

6. the preparation method of the lignin modification resol for moulding compound according to claim 1, is characterized in that: formaldehyde used is that mass percent concentration is the formaldehyde of 37-40%.